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Half-Fan Weighting Artifacts #92
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That's weird. I simulated data with your geometry and I did not get an artifact. If you are able to send your data to me, I can take a look it at. |
@lc82111 I guess that your thinking ring artifact is a real ring of your target sample. As you can see the projection image, there is a circle tap on top of cylinder. Those border area of this tap may be a ring. |
@kylechampley Thanks for your kind help. The raw projections can be found at this link: https://drive.google.com/file/d/1xb7X9mQo2kcIhWD_UGi40JXHCmd-6zQq/view?usp=sharing |
@hws203 Thanks for the suggestion. However, I believe the ring artifact I'm observing is not a physical characteristic of the sample. The phantom is flawless, and the ring and central dark region are absent in the full-scan data. |
@lc82111, the data in the link has no air scan projection. Could you send this and any other calibration files you have? |
Well, I tried to reconstruct without the air scan data and I think I got something good. It is different from what you showed, but there is still that inner circle. I do think this inner circle is real. Here is my result. And you can see that the inner cylinder is indeed in the raw data, so it is indeed real. See this projection: |
Here is the script I used. I turned your dicom files into tiff files before running the reconstruction.
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This ring artifact appears to be more prominent in RTK reconstruction as below: Furthermore, I believe the ring artifact is likely attributed to the RTK DDF (Displaced Detector Filter) weighting, as evidenced by the abrupt changes in the weighted image: Therefore, I utilized LEAP CT to validate my hypothesis. |
I believe this is a cone-beam artifact caused by the void cylinder at the bottom of that projection. Notice that the diameter of your dark circle is about the same size as the air cylinder at the bottom of the projection. I think you also have some beam hardening artifacts here. If you know something about the spectra, you could use LEAP's BHC algorithms to help mitigate this. |
I think so too. |
I observed a ring artifact in the overlapping region when using half-fan weighting. Are there any solutions?
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